Feed controlling device for a rock drilling mechanism



HIS ATTORNEY I D H\ 1 l T n M G u Whnwm J a J I Ne w I l: i F u F L 15 u Tammi-A n u. m

var/l Dec. 5, 1961 G. M. DICK FEED CONTROLLING DEVICE FOR A ROCK DRILLING MECHANISM Filed Sept. 25, 195] FIG. 3

United States Patent 3,011,569 FEED CONTROLLING DEVICE FOR A ROCK DRILLING MECHANISM George M. Dick, Sherbrooke, Quebec, Canada, assignor, by mesne assignments, to Ibis Enterprises Limited, Hamilton, Bermuda, a body corporate of Bermuda Filed Sept. 25, 1951, Ser. No. 248,219

2 Claims. (Cl. 175-124) often a diflicult matter to maintain a correct pressure in the feeding device under varying conditions of drilling. In the prior arrangements, the valve mechanism which controls the feeding pressure is housed in the feeding device and, owing to the facts that the angular relationship of the feeding device with respect to the rock drill varies constantly with the progress of drilling and that the entire mechanism vibrates at an extreme rate under the action of the reciprocatory element of the rock drill, the operator often has considerable difficulty in locating the control valve of the feeding device and manipulate it effectively in time to prevent the feeding device from thrusting the rock drill out of alignment with the hole being drilled.

In accordance with the practice of the invention, it is contemplated to incorporate all the pressure fluid controlling devices for both the rock drill and a feeding device pivotally connected thereto within the rock drill itself, more particularly, within the handle which the operator grasps for guiding the rock drill relatively to the work, and thereby eliminate the necessity for a frequent shifting of the operators hand from one part of the drilling mechanism to another.

It is accordingly an object of the invention to enable the feeding pressure of a feeding device pivotally connected to a rock drill to be conveniently controlled from a single position on the rock drilling mechanism which must, under all conditions of operation, be grasped by the hand of the operator.

Another object is to make the feeding pressure within the feeding device sensitively responsive to the will of the operator.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings accompanying this specification and in which similar reference numerals refer to similar parts,

FIGURE 1 is a side elevation, partly broken away, of a rock drilling mechanism equipped with a feed controlling device constructed in accordance with the practice of the invention,

FIGURE 2 is a side view of a detail,

FIGURE 3 is a view taken through FIGURE 2 on the line 33,

FIGURE 4 is a plan view, partly broken away, of the portion of the rock drilling mechanism shown in FIG- URE 3, and

FIGURE 5 is a transverse view taken through FIGURE 4 on the line 55.

Referring more particularly to the drawings and at first to FIGURE 1, 20 designates a rock drill which may be of the reciprocatory hammer type adapted for actuating a drill steel 21, and 22 is a fluid actuated feeding device which is pivotally connected at one end to an intermediate portion of the rock drill 20 by a pin, or bolt, 23 to permit of free variation in the angular relationship of the rock drill with respect to the feeding device.

The arrangement of the parts thus far set forth may be substantially like that shown in United States Patent No.

- 2,289,465, F. M. Slater and, as therein stated, the rock drill 20 may be of a conventional type known to the trade as a jackhammer. Likewise, the feeding device 22 consists of a piston member 24 and a cylinder member 25. The latter is the stationary element of the feeding device and has a pointer 26 threadedly connected to its lowermost end for engagement with a supporting surface. The piston 24 is hollow having a passage 27 extending therethrough for conveying pressure fluid into the cylinder 25 to act against the lower end 28 of the piston for press ing the rock drill toward the work.

Communication between the source of pressure fluid supply and the drilling mechanism is controlled by a throttle valve 29 in the rock drill 20. The pressure fluid supply for the rock drill may pass from the throttle valve 29 through the usual passages provided for the purpose, and the pressure fluid supply for the feeding mechanism 22 flows through a passage 30 in the casing of the rock drill and in an arm 31 and a grip member 32 integral with the arm.

The arm 31 projects laterally from an end of the grip member 32 and is secured fixedly to the casing of the rock drill by a bolt 33. The opposite end of the grip member 32 is preferably also supported, as by a brace 34 one end of which encircles the grip member and the other end is secured fixedly to the rock drill casing by a screw 35. The grip member 32, which serves as a handle for guiding the rock drill with respect to the work, consists of two parts, the one on the arm 31 being designated 36 and the other part is designated 37 and is threaded internally at one end for connection with threads 38 on the free end of the part 36.

In the free end portion of the part 36 is a bore 39 which is in constant communication with the passage 30 and serves as a chamber for an axially movable valve 40 which has an enlarged body 41 lying within a cavity 42 in the part 37. The free end of the valve 40 constitutes a pressure surface 43 and is constantly exposed to pressure fluid tending to move the valve out of the bore 39, and in said valve is a passage 44 which is also in constant communication with the passage 30 and conveys pressure fluid to ports 45 that open into the periphery of the valve 40. The pressure of the fluid acting against the surface 43 for opening the valve is augmented by a spring 46 which encircles the body 41 and is interposed between the part 36 and an external flange 47 on the body 41.

The degree of opening movement of the valve 40 is controlled by means arranged on the grip member and consisting of a plug 48 threaded into a recess 49 in the outer end of the part 37 of the grip member. The inner end 50 of the plug 48 serves as an abutment for the adiacent end of a stem 51 which may be integral with the body 41 and is slidable in a bore 52 in the grip member. The plug 48 has a stem 53 which projects from the end of the grip member and carries a cup-shaped member 54 which encircles the end of the grip member and is fastened to the stem 53 by a screw 55.

Suitable means are provided for preventing unauthorized rotation of the plug 48 and a consequent shifting of the valve 40. To this end the member 54 is provided interiorly with serrations 56 for engagement with a ball 57 that lies in the wall of the end portion of the grip member and is pressed yieldingly into the serrations 56 by a band spring 58 in the end of the grip member and encircling the stem 53.

In order to vent the cavity 42 to the atmosphere in the closed position of the valve the stem 53 and the plug 48 are respectively provided with passages 59 and 60 that register wtih each other, and at the inner end of the passage 59 is a port 61 to open into the cavity 42 and -which is so located that it will be blanked off by the wall of the bore 52 when the valve 40 occupies its open postion. The passage 60 is in constant communication with the space occupied by the band spring 58 through ports 62 in the plug 48, and the fluid entering such space from the ports 62 may escape to the atmosphere through the serrations 56 in the member 54.

In the open position of the valve 40 the pressure fluid passes from the ports 45 into the cavity 42 and flows from said cavity through a passage 63 in the part 36 of the grip member and in the arm 31. The outer end of the passage 63 is threaded for the accommodation of a suitable fitting 64 of a conduit 65 which is connected at its opposite end to the piston 24 and in communication with thepassage 27 in said piston. The conduit 65 is of the flexible type to permit of free pivotal movement of the feeding device with respect to the rock drill without hindrance by the conduit.

Means are provided for effecting the release of pressure fluid from the cylinder whenever the pressure therein tends to tilt the rock drill out of axial alignment with the hole being drilled. To this end the part 36 of the grip member is provided wtih a relief valve mechanism comprising a sleeve 66 which extends part way into a recess 67 that bisects, at its inner end, the passage 63. The interior of the sleeve 66 constitutes a guideway 68 for the stem 69 of a poppet valve 70 which is held to a seat 71 at the inner end of the guideway 68 by a spring 72 interposed between the bottom of the recess 67 and the valve 70.

The stem 69 of the poppet valve projects from the sleeve where it may be conveniently engaged by the operator for unseating the valve, and in the periphery of the stem is an annular groove 73 through which pressure fluid may flow, in the unseated position of the valve, from the recess 67 to an atmospheric exhaust port 74 in the sleeve 66 and the grip member.

In the operation of the device, and assuming the drilling mechanism to occupy a substantially correct operative position with respect to a working surface and the throttle valve 29 to be in the open position, the member 54 is rotated to thread the plug 48 outwardly in the grip member to a position that will permit the valve 40 to move out of the bore 39 for uncovering one or all of the ports 45. The valve 40 will be caused to follow the outward movement of the plug 48 by the pressure fluid acting against the surface 43 and by the force of the spring 46.

In the open position of the valve 40 pressure fluid flows from the passage 30 through the channels in the valve 40 into the cavity 42, thence through the passage 63, the recess 67 and the conduit 65 and through the passage 27 into the cylinder 25. Such pressure fluid acts against the lower end of the pston 24 and urges the rock drill 20 in the direction of the work in accordance with the rate of penetration of the working implement 21 thereinto.

Whenever conditions in the hole being drilled require a lessening of the feeding pressure in the cylinder 25, as when, for example, the working implement encounters a seam in the rock or enters a pocket of soft material and in consequence of which it may become necessary to decrease the feeding pressure in the cylinder 25, the member 54 is rotated to shift the valve 40 to a position in which the ports 45 are blanked off by the wall of the bore 39. The feeding cylinder 25 will thereby be cut off from pressure fluid supply and, if required, the pressure within the feeding cylinder may then be decreased by unseating the valve 70. Such movement of the valve 70 is effected by manual pressure against the stem 69 and in the open position of said valve pressure fluid escapes from the cylinder 25 through the passage 27 in the piston 24, the conduit 65 and through the recess 67, the annular groove 73 and through the passage 74 to the atmosphere.

When conditions within the drill hole again permit the use of a normal feeding pressure in the cylinder 25 the valve 70 is released andr the spring 72 will return it to its seat to cut off the furtherescape of pressure fluid to the atmosphere. The member 54 is then manipulated to allow the spring 46 to act for shifting the valve 40 and again uncover the ports 45 for establishing communication between the source of pressure fluid supply and the feeding cylinder.

From the foregoing description it will be readily apparent that the action of the feeding device of the drilling mechanism may be nicely controlled from a point which is constantly grasped by the hand of the operator for guiding the rock drill with respect to the work and without requiring the shifting of such hand from one position to another.

I claim:

1. In a feed controlling device for a rock drilling mechanism, the combination of a rock drill and'a fluid actuated feeding device pivotally connected thereto to permit of rocking movement of the rock drill with respect to the feeding device, a grip member at the rear end of the rock drill and extending rearwardly thereof for guiding said rock drill with respect to the work, consisting of an arm extending rearwardly and rigidly attached to the rock drill and a transverse portion to be grasped by the operator, a supply passage for pressure fluid in the rock drill and passing through said arm of the grip member, a pressure fluid conveying conduit extending from the supply passage to the feeding device, valve means on the grip member for controlling the flow of pressure fluid through the supply passage and the conduit to the feeding device, an exhaust passage in the grip member for the supply passage and a second independent valve means on the grip member for valving fluid from the feeding device to the exhaust passage to lower the feeding pressure within the feeding device.

2. In a feed controlling device for a rock drilling mechanism, the combination of a rock drill and a fluid actuated feeding device pivotally connected thereto to permit of rocking movement of the rock drill with respect to the feeding device, a grip member at the rear end of the rock drill and extending rearwardly thereof for guiding said rock drill with respect to the work, consisting of an arm extending rearwardly and a transverse portion to be grasped by the operator, a supply passage for pressure fluid in the rock drill and passing through said arm of the grip member, a pressure fluid conveying conduit extending from the supply passage to the feeding device, valve means on the grip member-for controlling the flow of pressure fluid through the supply passage and the conduit to the feeding device, said valve means being mounted to be operated at one end of said transverse portion, an exhaust passage in the grip member for the supply passage and a second independent valve means on the opposite end of the transverse portion of said grip member for valving fluid from the feeding device to the exhaust passage to lower the feeding pressure within the feeding device.

References Cited in the file of this patent UNITED STATES PATENTS 1,690,859 Gilrnan Nov. 6, 1928 1,774,186 Rundqvist Aug. 26, 1930 1,928,700 Nell Oct. 3, 1933 2,075,572 Curtis Mar. 30, 1937 2,274,728 Osgood Mar. 3, 1942 2,289,465 Slater July 14, 1942 2,461,528 Curtis et al Feb. 15, 1949 2,908,482 Curtis et al. Oct. 13, 1959 FOREIGN PATENTS 423,578 France Feb. 18, 1911 i his, 

